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Re: [v3 1/2] sched/clock: interface to allow timestamps early in boot

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Hi Pasha,

At 08/14/2017 11:44 PM, Pasha Tatashin wrote:
> Hi Dou,
>
> Thank you for your comments:
>
>>>  {
>>>      x86_init.timers.timer_init();
>>>      tsc_init();
>>> +    tsc_early_fini();
>>
>> tsc_early_fini() is defined in patch 2, I guess you may miss it
>> when you split your patches.
>
> Indeed, I will move it to patch 2.
>
>>> +static DEFINE_STATIC_KEY_TRUE(__use_sched_clock_early);
>>> +static bool __read_mostly sched_clock_early_running;
>>> +
>>
>> In my opinion, these two parameters are repetitive, I suggest remove
>> one.
>>
>> eg. remove sched_clock_early_running like below
>> First, static DEFINE_STATIC_KEY_FALSE(__use_sched_clock_early);
>
> We can't change the static branches before jump_label_init() is called,
> and we start early boot timestamps before that
>

I understood, I was wrong, thanks for your explanation.

Thanks
	dou.

> This is why having two booleans is appropriate: one that can be changed
> early in boot, and another to patch the hotcode in order to keep good
> performance after boot.
>
> I will update comment before __use_sched_clock_early explaining the
> reason why we need two of them.
>
> Thank you,
> Pasha
>
>
>

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Re: [v3 1/2] sched/clock: interface to allow timestamps early in boot Dou Liyang <douly.fnst@cn.fujitsu.com> - 2017-08-14 06:40 +0200
  Re: [v3 1/2] sched/clock: interface to allow timestamps early in boot Pasha Tatashin <pasha.tatashin@oracle.com> - 2017-08-14 17:50 +0200
    Re: [v3 1/2] sched/clock: interface to allow timestamps early in boot Dou Liyang <douly.fnst@cn.fujitsu.com> - 2017-08-15 11:30 +0200

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